Overall concordance correlation coefficient (OCCC) for agreement on a continuous measure based on Lin (1989, 2000) and Barnhart et al. (2002).
Usage
epi.occc(dat, na.rm = FALSE, pairs = FALSE)
"print"(x, ...)
"summary"(object, ...)
Arguments
dat
a matrix, or a matrix like object. Rows correspond to cases/observations, columns corresponds to raters/variables.
na.rm
logical. Should missing values (including NaN) be removed?
pairs
logical. Should the return object contain pairwise statistics? See Details.
x, object
an object of class epi.occc.
...
further arguments passed to print methods.
Value
An object of class epi.occc with the following list elements (notation follows Barnhart et al. 2002):
occc: the value of the overall concordance correlation coefficient ($rho.o^c$),
oprec: overall precision ($rho$),
oaccu: overall accuracy ($chi^a$),
pairs: a list with following elements (only if pairs = TRUE, otherwise NULL;
column indices for the pairs (j,k) follow lower-triangle column-major rule
based on a ncol(x) times ncol(x) matrix),
ccc: pairwise CCC values ($rho_jk^c$),
prec: pairwise precision values ($rho_jk$),
accu: pairwise accuracy values ($chi_jk^a$),
ksi: pairwise weights ($ksi_jk$),
scale: pairwise scale values ($v_jk$),
location: pairwise location values ($u_jk$),
data.name: name of the input data dat.
Details
The index proposed by Barnhart et al. (2002) is the same as the index suggested by Lin (1989) in the section of future studies with a correction of a typographical error in Lin (2000).
References
Barnhart H X, Haber M, Song J (2002). Overall concordance correlation coefficient for evaluating agreement among multiple observers. Biometrics 58: 1020 - 1027.
Lin L (1989). A concordance correlation coefficient to evaluate reproducibility. Biometrics 45: 255 - 268.
Lin L (2000). A note on the concordance correlation coefficient. Biometrics 56: 324 - 325.